1. Field of the Invention
The present invention relates to a head cleaning apparatus and a droplet ejection apparatus, and more particularly to a technology of bringing a web into pressing contact with a nozzle surface of a droplet ejection head to perform cleaning.
2. Description of the Related Art
If the droplet ejection head continuously performs a droplet ejection, dirt (such as mist and paper dust) is gradually attached to a nozzle surface. The dirt induces bending of the droplet ejection. Accordingly, in the droplet ejection head, cleaning of a nozzle surface is periodically performed.
The cleaning of the nozzle surface, for example, is performed by wiping the nozzle surface with a blade (wiper) or the web.
For example, in JP2002-019133A, a method of cleaning by wiping the nozzle surface with the blade is disclosed. In JP2002-019133A, in order to prevent the blade from scratching an outlet region of the nozzle and deforming the outlet region of the nozzle during the wiping operation, a contact portion with the nozzle surface of the blade is formed to be recessed.
In addition, in JP2010-099880A, as a method of cleaning the droplet ejection head having an ascendable and descendible nozzle protection member at both sides of the nozzle surface, a method is disclosed which wipes the nozzle surface with the blade by pushing up the nozzle protection member using a roller member during cleaning and exposing the nozzle surface.
On the other hand, in JP2011-067985A, a method of wiping the nozzle surface using the web is disclosed. In JP2011-067985A, a method is proposed in which, as means for bringing the web into pressing contact with the nozzle surface, a first pressure roller and a second pressure roller are provided, and both end portions of the web are pressed to be brought into pressing contact with the nozzle surface using the first pressure roller, and the center of the web is pressed to be brought into pressing contact with the nozzle surface using the second pressure roller.
In addition, in JP2010-274533A, in order to prevent the nozzle surface from being damaged by wiping, a method of forming a constant gap between the nozzle surface and the web to wipe is disclosed.